Air at high pressure, i.e. at 2.5 M

Air at high pressure, i.e. at 2.5 MPa or more, is required for starting main and auxiliary engines in motorships and in steamers, often for the latter purpose. hi both, air at low pressure, say at 0.6 MPa or less is required for much remote or temperature or pressure controlled equipment, for which purpose it must be clean and oil-free. A typical simple h.p. air system, it is a requirement that there shall be at least two reservoirs whose combined capacity allows (all) the main engines to be started twelve times if they are reversible and six times if they are not, while the compressors are idle.1. In the starting air system of the auxiliary engines, the air pressure should be ________. A. less than 2.5 MPa B. at least 2.5 MPa C. less than 0.6 MPa D. more than 0.6 MPa2. In the control system, the controlling air pressure should not be more than________.. A. 2.5 MPa B. 1.9 MPa C. 0.6 MPa D. 3.1 MPa3. Which of the following statements is not true? A. In the steamer vessels the main engines are started by compressed air. B. In the steamer vessels the auxiliary engines are started by compressed air. C. The compressed air being used as controlling medium should be filtered. D. There are at least two air bottles in the ships.4. The air reservoirs should be able to start the engines ________ times when they are reversible. A. 25 B. 6 C. 12 D. 18